There are two ways to upload files. Always remember to upload files to your public_html directory.

cPanel File Manager

To use cPanel's File Manager first login to cPanel the find the link marked "File Manager", then once it is open navigate to the folder that you want to upload to and click the upload button. This are pretty straightforward after that.

Files Section in cPanel

FTP

To use FTP you need a FTP client (Filezilla is recommended but you must disable multiple connection otherwise the firewall may block you.)

The FTP details you need for your FTP client are:

Host: your account's primary (main) domain

Port: 21

User: your cPanel user name

Password: your cPanel password

* x10hosting does not endorce or recommend a specific FTP client. The clients explained and pictured in this article are merely provided as example.